It seems you may have missed an important point about Analog FastSPICE – it doesn’t compete in the traditional fastSPICE segment. We often refer to traditional fastSPICE as “digital fastSPICE” because that was the original target segment and remains its strong suite. HSIM, NanoSim, UltraSim, ADiT, FineSim – they are all digital fastSPICE simulators in that they tradeoff accuracy for performance. These simulators are great for digital designs and memories where 2%,5%, and even 10% inaccuracy compared to SPICE is “good enough.” Giving up that accuracy enables them to run sometimes 100x or more faster than traditional SPICE. Digital fastSPICE simulators will continue to do very well in digital and memory applications. We tell customers who don’t need real full SPICE accuracy (i.e., to the SPICE noise floor, not within a few percent) that they should use digital fastSPICE. Analog FastSPICE only makes sense for analog and RF circuits that need absolutely full SPICE accuracy.

As its name implies, we believe Analog FastSPICE defines a new category of circuit simulator. Traditional SPICE will continue to be best for block-level analog, traditional fastSPICE (a.k.a., digital fastSPICE) will continue to be best for digital and memory designs, and Analog FastSPICE is the best tool for complex blocks and top-level analog and RF circuits.